Multiplication of two polynomials using linked list in java

//Class for polynomial linked list
import java.util.Scanner;

class Node {
public int numC;
public int numE;
public Node next;

// elementary constructor
public Node() {
numC = 0;
numE = 0;
next = null;
}

// constructor with two argument
public Node(int c, int e) {
numC = c;
numE = e;
next = null;
}

// primary constructor
public Node(int c, int e, Node n) {
numC = c;
numE = e;
next = n;
}

// accessor method
public int getCo() {
return numC;
}

public int getEx(){
return numE;
}

// accessor method
public Node getNext() {
return next;
}

// mutator method
public void setCof(int c){
numC = c;
}

public void setExp(int e){
numE = e;
}
// mutator method for next
public void setNext(Node nextNode) {
next = nextNode;
}
} // end of class Node



class Polynomial {
private Node front;
public Polynomial(){
front = null;
}

//read coefficient fx
public int readCoFx(){
Scanner scan = new Scanner(System.in);
int coef = 0;

System.out.print("Enter Coefficient or 0 to skip to next equation: ");
coef = scan.nextInt();
return coef;
}
//read coefficient gx
public int readCoGx(){
Scanner scan = new Scanner(System.in);
int coef = 0;

System.out.print("Enter Coefficient or 0 to end program: ");
coef = scan.nextInt();
return coef;
}
//read exponent
public int readEx(){
Scanner scan = new Scanner(System.in);
int exp = 0;

System.out.print("Enter Exponent: ");
exp = scan.nextInt();
return exp;
}

//insert Node
public void insert(int coef, int exp){
    Node temp = new Node(coef, exp, null);
    //insert temp to 1st if empty
    if (front == null)
        front = temp;
    else {

        Node p = null;
        Node q = front;
    //insert in front if exponent is higher
        if (temp.getEx() > q.getEx()){
            temp.setNext(front);
            front = temp;
        } else 
            {//insert at middle or end
    while (q != null && q.getEx() > temp.getEx()){

        p = q;
        q = q.getNext();
       }

    p.setNext(temp);
    temp.setNext(q);

    }
    }
}
public void mulInsert(int coef, int exp){
    //Node temp = new Node(coef, exp, null);
    //insert temp to 1st if empty
        System.out.println("coef="+coef+"exp="+exp);
        if (front == null)
                front = new Node(coef,exp,null);
        else {

                    Node p = null;
                    Node q = front;
        //insert in front if exponent is higher
                if (exp > q.getEx()){
                        Node temp = new Node(coef,exp,null);
                        temp.setNext(front);
                        front = temp;
                } else 
                    {//insert at middle or end
                        while (q != null && q.getEx() >= exp){
                            if (q.getEx() == exp)
                            {
                                q.numC += coef;
                                q=q.getNext();
                                continue;
                            }
                            p = q;
                            q = q.getNext();
                        }

                   Node temp = new Node(coef,exp,null);
                    p.setNext(temp);
                    temp.setNext(q);

                }
    }

}

//print function for the equations
public void print(){
Node p = front;
while(p != null){
System.out.print("("+p.getCo()+ "x" + p.getEx()+")");
p = p.getNext();
}
System.out.println("");
}


//function to add polynomials
public static Polynomial addPoly(Polynomial poly1, Polynomial poly2){
Polynomial tempPoly = new Polynomial();
//if poly1 exp is > poly 2 exp then power = poly 1 exp else power = poly 2 exp
int power = (poly1.front.getEx() > poly2.front.getEx()) ? poly1.front.getEx() : poly2.front.getEx();

while (power >=0){
    Node n1 = poly1.front;
    while (n1 != null){
        if (n1.getEx() == power)
            break;
        n1 = n1.getNext();
    }

    Node n2 = poly2.front;
    while (n2 != null){
    if (n2.getEx() == power)
        break;
    n2 = n2.getNext();
    }

    if((n1 != null) && (n2 != null))
        tempPoly.insert((n1.getCo() + n2.getCo()), n1.getEx());
    else if (n1 != null)
        tempPoly.insert(n1.getCo(), n1.getEx());
    else if (n2 != null)
        tempPoly.insert(n2.getCo(), n2.getEx());
    power--;
}
return tempPoly;
}

public static Polynomial mulPoly(Polynomial poly1, Polynomial poly2){
Polynomial tempPoly = new Polynomial();

Node n1 = poly1.front;


while (n1 != null ){
Node n2 = poly2.front;
while(n2 != null){
        tempPoly.mulInsert((n1.getCo()*n2.getCo()),(n1.getEx() + n2.getEx()));
    n2 = n2.getNext();
}
n1= n1.getNext();
}
return tempPoly;
}
}

//driver
public class PolyDrive {
public static void main(String [] args){
Polynomial poly1 = new Polynomial();
Polynomial poly2 = new Polynomial();
Polynomial poly3 = new Polynomial();
Polynomial poly4 = new Polynomial();
int co;
int ex;

do {
co = poly1.readCoFx();
if(co != 0){
ex = poly1.readEx();
poly1.insert(co, ex);
}
//poly1.print();
} while (co != 0);

do {
co = poly2.readCoGx();
if(co != 0){
ex = poly1.readEx();
poly2.insert(co, ex);
}
//poly2.print();
} while (co != 0);
poly1.print();
poly2.print();
//poly3 = Polynomial.addPoly(poly1,poly2);
//poly3.print();
poly4 = Polynomial.mulPoly(poly1,poly2);
poly4.print();
}
}